Wastewater effluent from alkaloid processing plants has the potential adverse environmental influences. Mathematical modelling and simulations were carried out using computational fluid dynamics of mass and momentum transfer in a hollow fibre membrane extractor. Conservation equations were derived for tyramine extraction in the membrane extractor and solved based on the finite element method. Model findings based on the computational fluid dynamics validated well with the experimental data. The results showed that increase in organic-phase flow rate, as well as the fibre length and its porosity, has a positive impact on the performance of the extractor, whereas the enhancement of aqueous-phase flow rate led to the reduction of tyramine extraction.

Biogenic amines (BAs) are natural toxicants produced during the metabolism of their precursor amino acids or due to the proteolytic activities of some microorganisms. The objective of this study was to estimate the formed BAs in five types of the most commonly consumed and retailed cheese in Egypt. The examined cheese types included Feta, Karish, Mozzarella, Rumy, and Mish. Besides, the total mesophilic (TMC) and total psychrophilic (TPsC) bacterial counts were investigated. Furthermore, the estimated daily intakes (EDI) of BAs via the ingestion of various types of cheese were calculated, and their potential health risks were discussed. The achieved results indicated the formation of histamine (HIS), tyramine (TYR), cadaverine (CAD), putrescine, spermine, and spermidine at different concentrations. Except for Feta cheese, all samples (100%) of other cheese types had HIS concentrations higher than the established maximum permissible limits. Mish cheese contained the highest concentrations of total BAs, particularly, HIS, TYR, and CAD. TBA content showed significant positive correlations with TMC in the examined cheese types. The recorded EDI values of the different BAs in the current study would not have adverse effects. However, excessive consumption of cheese contaminated with BA might have serious health implications such as symptoms of histamine poisoning. Therefore, the adoption of strict hygienic measures during the production, storage, and distribution of cheese is highly recommended to reduce the formation of BAs in cheese.